The invention relates to the use of active optical materials to perform logic operations using optical signals.
In the field of digital electronics, specific logic functions are performed by electronic circuits. These logic functions are commonly known by those skilled in the art of digital electronics. Examples of the logic functions and their electronic analogs are known as the AND gate, the NAND gate, the OR gate, the NOR gate and various other logic based circuits that can be designed to perform particular electronic functions. These functions are based on a truth table or logic table that defines the output when a set of selected input conditions are present. It is possible to design electronic circuits so that they replicate the results of these truth tables. In these designs substantial flexibility is available by manipulating the outputs of the gates with electronic changes such as the addition of a state inverter, which can be used with circuits to switch the nature of one gate to that of another gate or can otherwise be used to invert the digital state of a signal. Often these logic circuits are utilized in large numbers to make electronic computers.
The use of optically active materials, especially semiconductor lasers and optical fibers for data transmission, has led to increasing interest in optically driven circuits that can be driven directly by incoming photons carrying information. Eliminating the need to switch from an optical to an electrical signal improves the ability of networks to handle more data.
If entire computers could be built with optically driven circuits, they could also operate at higher speed. Because of this, it has been a goal in computer technology to build computers using optically based switching circuitry. It is thought that such optically based circuits will provide advantages in addition to improved computing speed and could find application in advanced computing techniques such as quantum computing.
In addition these optically based circuits would improve the performance and abilities in various other applications such as transmission networks and resistance to ElectroMagnetic Pulse (EMP), and other electromagnetic disturbances. However, there are a myriad of challenges before technologists to accomplish such advanced goals. In particular the creation of suitable optical logic circuits has challenged computer technologists giving rise to a need for improved optical switches that can operate individually or be made into logic gates or other information processing constructions.